LG B2050 Service Manual
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- LG B2050 | Service Manual - Page 1
B2050Cover_3.3-0419 2005.4.20 1:7 PM Page 2 Service Manual Service Manual B2050 Model : B2050 P/N : MMBD0049101 Date : April 2005 / Issue 1.0 - LG B2050 | Service Manual - Page 2
Reset [MENU 6 109 9.7 S/W version [MENU 7 109 10. STAND ALONE TEST 110 10.1 Introduction 110 10.2 Setting Method 110 10.3 Means of Test 111 4. TROUBLE SHOOTING 46 4.1 RX Trouble 46 4.2 TX Trouble 53 4.3 Power On Trouble 61 4.4 Charging Trouble 63 4.5 Vibrator Trouble 65 4.6 LCD Trouble - LG B2050 | Service Manual - Page 3
as long as repair is not done. C. Changes in Service A local telephone company may make changes in its communicationsfacilities or procedure. If these changes could reasonably be expected to affect the use of the this phone or compatibility with the network, the telephone company is required to give - LG B2050 | Service Manual - Page 4
the following to the end user. F. Pictures The pictures in this manual are for illustrative purposes only; your actual hardware may look slightly different. G. Interference and Attenuation Phone may interfere with sensitive laboratory equipment, medical equipment, etc.Interference from unsuppressed - LG B2050 | Service Manual - Page 5
1. INTRODUCTION 1.3 Abbreviations For the purposes of this manual, following abbreviations apply: APC BB BER CC-CV DAC Minimum Shift Keying General Purpose Interface Bus Global System for Mobile Communications International Portable User Identity Intermediate Frequency Liquid Crystal Display - LG B2050 | Service Manual - Page 6
TDMA UART VCO VCTCXO WAP Power Amplifier Module Printed Circuit Board Programmable Gain Amplifier Phase Locked Loop Public Switched Telephone Network Radio Frequency Receiving Loudness Rating Root Mean Square Real Time Clock Surface Acoustic Wave Subscriber Identity Module Sending Loudness Rating - LG B2050 | Service Manual - Page 7
2. PERFORMANCE 2. PERFORMANCE 2.1 H/W Features - 6- - LG B2050 | Service Manual - Page 8
2. PERFORMANCE -7- - LG B2050 | Service Manual - Page 9
2. PERFORMANCE 2.2 Technical Specification - 8- - LG B2050 | Service Manual - Page 10
2. PERFORMANCE -9- - LG B2050 | Service Manual - Page 11
2. PERFORMANCE - 10 - - LG B2050 | Service Manual - Page 12
2. PERFORMANCE - 11 - - LG B2050 | Service Manual - Page 13
2. PERFORMANCE - 12 - - LG B2050 | Service Manual - Page 14
part. The Aero I transceiver is the integrated RF front end for multi-band GSM/GPRS digital cellularhandsets and wireless data modems. The integrated solution eliminates the IF SAW filter, externallow noise amplifier (LNAs) for three bands, transmit and RF voltage controlled oscillator(VCOmodules - LG B2050 | Service Manual - Page 15
1930MHz ~ 1990MHz) are fed into the antenna or Mobile switch. The Front End Module(FL500) is used supports theDCS 1800 (1805-1880 MHz) band. The PCS input supports the PCS 1900 (1930-1990MHz) band. The LNA inputs are matched to the 150Ωbalanced output SAW filters through externalLC matching networks - LG B2050 | Service Manual - Page 16
3. TECHNICAL BRIEF Figure 3-2 SI4205 RECEIVER PART B. Intermediate frequency (IF) and Demodulation A quadrature image-reject mixer downconvertsthe RF signal to a 100KHz intermediate frequency (IF) with the RFLO from the frequency synthesizer. The RFLO frequency is between 1737.8 to 1989.9 MHz, and - LG B2050 | Service Manual - Page 17
and one for the DCS 1800 (1710-1785 MHz) and PCS 1900 (1850-1910MHz) bands. GSM RFOG PA DCS/PCS RFOG PA Figure 3-3 SI4205 TRANSMITTER PART A. IF Modulator The sideband rejection and produces a GMSK modulated signal. The baseband software is able to cancel out differential DC offsets in the - LG B2050 | Service Manual - Page 18
loop filter, and a fully integrated TXVCO. The TXVCO is centered between the DCS 1800 and PCS 1900 bands, and its output is divided by 2 for the GSM 850 and E-GSM 900 Additionally, the SWAP bit in register 03h can be used to manually exchange the I and Qsignals. Low-pass filters before the OPLL - LG B2050 | Service Manual - Page 19
a 13 or 26 MHz reference frequency. For receive mode, the RF1 PLL phase detector update rate (ƒø ) should be programmed ƒø = 100 kHz for DCS 1800 or PCS 1900 bands, and ƒø = 200 kHz for GSM 850 and E-GSM 900 bands. For transmit mode, the RF2 and IF PLL phase detector update rates are - LG B2050 | Service Manual - Page 20
for use as the final RF amplifier in GSM850, EGSM900, DCS and PCS handheld digital cellular equipment and other applications in the 824MHz to 849MHz, RF3166 incorporates RFMD's latest VBATT tracking circuit, which monitors battery voltage and prevents the power control loop From reaching saturation - LG B2050 | Service Manual - Page 21
of AD6537B (U101). MIC5255 (U702) supplies power to transceiver (SI4205, U500). One port of AD6537B supplies power to VCTCXO (X500). Supplier U702(VRF) U101(VVCXO) Battery(VBAT) Voltage 2.85 V 2.75 V 3.4 ~ 4.2 V Powers U500 X500 U501, U702 Table 3-2 RF POWER SUPPLIERS enabled signal - 20 - - LG B2050 | Service Manual - Page 22
3. TECHNICAL BRIEF CLKON VBAT C533 10u U702 1 IN 2 3 GNO EN MIC5255-85BM5 5 OUT 4 BYP C734 0.01u RF2VBS C534 10u (1608) Table 3-7 RF LDO CIRCUIT DIAGRAM - 21 - - LG B2050 | Service Manual - Page 23
Keypad Matrix Backlight/ Service Light Flash 16-bit SRAM 8 or 16 bit (optional) DISPLAY (Parallel) serial display Accessory Devices e.g BATTERY SIM Application Processor USB Data Port BSDI BASE BSIFS BAND BSDO I/Q Serial BSOFS Port CSDI CSDO CSFS INT control serial port MCLKEN MCLK RESET - LG B2050 | Service Manual - Page 24
SRAM 2. DSP Subsystem • 16-bit Fixed Point DSP Processor • 91 MIPS at 1.7V • 16K word Data and 16K word Program SRAM • 4K word Program Instruction Cache • Architecture supports Full Rate, Enhanced Full Rate, Half Rate,and AMR speech Encoding/Decoding Algorithms 3. Peripheral Subsystem • Shared on - LG B2050 | Service Manual - Page 25
IC has own CS pin It controls dimming mode of LCD module. (GPIO_5) This pin resets LCD module. This signal comes from DBB directly Enable writing to LCD Driver. 2.8V voltage is supplied to LCD driver IC LCD_ID (GPIO 16) It determines the maker of LCD module. LCD_BL_EN It controls back-light - LG B2050 | Service Manual - Page 26
PA_EN (GPO 16) RF LDO Enable/Disable PAM Enable/Disable S_EN (GPO 19) S_DATA (GPO 20) S_CLK (GPO 21) RF_PWR_DWN(GPO 4) PLL Enable/Disable Serial Data to PLL Clock to PLL Power down Input Table 3-5 RF CONTRON SIGNALS DISCRIPTION - 25 - - LG B2050 | Service Manual - Page 27
GPIO_23) Description This pin receives and sends data to SIM card. This model can support only 3.0 volt interface SIM card. Clock 3.25MHz frequency. Reset SIM block Table 3-6 SIM CONTRON SIGNALS output signal. Interrupt signals are generated by the Auxiliary ADC, audio, and charger modules. - 26 - - LG B2050 | Service Manual - Page 28
communication bus network. It alsoincludes functions. The code used to supports all the GSM terminal software, including the layer 1, 2 and 3of the GSM protocol stack, the MMI, and applications software such as data services terminal functions: keyboard, battery supervision, radio and display - LG B2050 | Service Manual - Page 29
Ram GMSK Filter Filter ADC DAC DAC DAC DAC ADC ADC LEDs Othello Crystal & Varactor Tone Filter DAC ASPORT Filter ADC Mic Battery Charger 8 Voltage Regulators Switch Headphones or Headset VCORE: 1.8 V, 80mA VMEM: 1.8 or 2.8V, 150mA VEXT: 2.8V, 170mA VSIM: 1.8 or 2.85V, 20mA VRTC: 1.8V - LG B2050 | Service Manual - Page 30
• Light Controllers 4. Audio Section • 8 kHz & 16 kHz Voiceband Codec • 48 kHz Monophonic DAC • Power Amplifiers 5. Power Management section • Voltage Regulators • Battery Charger • Battery Protection6. Digital Processor section • Control, Baseband, and Audio Serial Ports • Interrupt Logic - 29 - - LG B2050 | Service Manual - Page 31
3. TECHNICAL BRIEF 3.6.1 Baseband Transmit Section 1. The AD6537B Baseband Transmit Section is designed to support GMSK for both single-slotand multi-slot application. 2. The transmit channel consists of a digital GMSK modulator, a matched pair of 10-bit DACs and a matched pair - LG B2050 | Service Manual - Page 32
Voltage Reference • IDAC: 10 bits • The Auxiliary ADC provides : -Two differential inputs for temperature sensing. -A differential input for the battery charger current sensor CSFS CSDI CSDO AD6537B Control Serial Port AFC DAC Voltage Reference Aux ADC REFTXCM Light Controllers AFCDAC REFBB - LG B2050 | Service Manual - Page 33
channels.' 4. It interconnects with external devices like main microphone, main receiver, and headset. The descriptions of audio port used in B2050 are given bellow in detail. - AIN1P,AIN1N : Main microphone positive/negative terminal - AIN2P,AIN2N : Headset microphone positive/negative - LG B2050 | Service Manual - Page 34
Analog LDO Regulator Microphone LDO Regulator VCXO LDO Regulator VABB VMIC 2.5V, 1mA VVCXO 2.75V, 10mA Battery Charer VCHG GATEDRIVE BATTYPE ISENSE KEYON KEYOUT Power-on Reset Generator Figure 3-16 AD6537B POWER MANAGEMENT SECTION 1. Power up sequence logic 1. The AD6537B controls power on - LG B2050 | Service Manual - Page 35
3. TECHNICAL BRIEF AD6537B Thermal THERM Shutdown KEYON DDLO UVLO CHGDET VBAT VRTC DBBON VEXT VCXOEN VEXT mode Control Bit VSIMEn Control Bit POWERMODE Enable Digital Core LDO Regulator Mode Enable Memory Interface LDO Regulator Mode Enable External Interface Mode LDO Regulator Enable SIM - LG B2050 | Service Manual - Page 36
60Hz -Output voltage: DC 5.2V ( 0.2 V ) -Output current: Max 800mA ( 50mA ) 5. Battery -Li-ion battery (Max 4.2V, Nom 3.7V) -Standard battery: Capacity -830mAh CSFS CSDI CSDO AD6537B Control Serial Port Charge Timer Trouble Charge Chg. DAC Aux ADC INT Interrupt Logic VCHG GATEDRIVE ISENSE - LG B2050 | Service Manual - Page 37
CLOSE TO AD6537B R111 4.7 R114 4.7 C139 39p HEADSET_SPK_P HEADSET_SPK_N RINGTONE C140 C141 39p 39p REC_P REC_N From Headset Microphone LGND DGND C144 39p 39p To Headset Speaker SGND1 SGND2 Figure 3-19 B2050 HEADSET SPEAKER/MIC CIRCUIT (AD6537B) AIN3L R13 AIN3R R14 P15 AIN2P AIN2N R15 - LG B2050 | Service Manual - Page 38
,1% R352 15 R356 47K VBAT C324 0.1u LD306 R350 750 3 2 Q401 2SC5585 1 R358 10K R359 20 Figure 3-21 CIRCUIT FOR BATTERY CHARGING AT AD6537B In order to reduce time for trickle charging, additional circuit(Pre-charge circuit) was included.This circuit has supplied Max 160mA current into the - LG B2050 | Service Manual - Page 39
Active Screen Size Color Depth Resolution Pixel Size Spec. 28.022(H) X 28.022(V) 65,000 C14S02050 _MIDI_IRQ BATT_EPROM RINGTONE M JACK_DETECT RADIO_VOL_CTRL R117 DATA[00:15], LCD_ID, •_LCD_CS : MAIN LCD driver chip enable. MAIN LCD driver IC has own CS pin •LCD_RESET : This pin resets - LG B2050 | Service Manual - Page 40
3. TECHNICAL BRIEF _LCD_RESET DATA00 DATA01 DATA02 DATA03 DATA04 DATA05 DATA06 DATA07 ADD01 _LCD_CS _WR DATA08 DATA09 DATA10 DATA11 DATA12 DATA13 DATA14 DATA15 B1 B2 B3 G1 G2 G3 128X128 LCD CONNECTOR FL400 CSPEMI306A A1 FILTER1-1 A2 A3 FILTER2-1 A4 FILTER3-1 FILTER4-1 A5 $AV6 FILTER5-1 - LG B2050 | Service Manual - Page 41
35 for KEY_ROW5, as shown in Figure 3-27, except for the power switch, which is connected independently. Functions, the row and column lines of the keypad are connected to ports of AD6527. The columns are outputs, while the rows are inputs and have pull-upresistors built in. When a key is pressed - LG B2050 | Service Manual - Page 42
passed to the DSP section of AD6527 for processing (coding, interleaving etc). 2V5_VMIC R200 1K MIC_P MIC_N R203 R214 2.2K C213 39p C214 39p CLOSE TO MIC MIC200 1 2 OB4-15L42-C33L VA201 VA200 AVL5M02- AD6537B 3.10 Main Speaker In the case of B2050, The main speaker is driven directly from - LG B2050 | Service Manual - Page 43
3. TECHNICAL BRIEF 3.11 Headset Interface This phone chooses a 5 pin type headset which has 6 electrodes such as HEADSET_SPK_OUT_P, HEADSET_MIC_P, JACK_DETECT, HEADSET_SPK_OUT_N, RADIO_ANT. This type supports stereo sound Switching from Receiver to Headset Jack If jack is inserted, JACK_DETECT goes - LG B2050 | Service Manual - Page 44
3. TECHNICAL BRIEF 3.12 Key Back-light Illumination In key back-light illumination, there are 6 Blue LEDs in Main Board, which are driven by MIDI_KEY_BL1 and MIDI_KEY_BL2 signal from ML2871HB. KEY BACKLIGHT VBAT C318 1u C319 1u C320 1u C323 1u C321 1u C322 1u R344 R345 R346 47 47 47 R347 - LG B2050 | Service Manual - Page 45
3. TECHNICAL BRIEF 3.13 VIBRATOR The vibrator is placed in the folder cover and contacted to LCD MODULE. The vibrator is driven from MIDI_VIBRATOR from ML2871HB. VIBRATOR VBAT MIDI_VIBRATOR C300 4.7u R315 1.5K U401 MIC5255-2.85BM5 1 5 IN OUT 2 GND 3 EN BYP 4 C302 0.01u C303 1u CN301 1 - LG B2050 | Service Manual - Page 46
4. TROUBLE SHOOTING 4.1 RX Trouble TEST POINT 13Mhz OSCILLATOR Figure 4-1(a) 3. TECHNICAL BRIEF Mobile SW FEM TRANCEIVER LDO - 45 - - LG B2050 | Service Manual - Page 47
4 . TROUBLE SHOOTING Checking Flow START HP8960 : Test mode 62 CH, 7 level setting (TCH) 62CH, -60dBm setting (BCCH) Spectrum analyzer setting Oscilloscope setting Check regulator circuit Check VCTCXO Check FEM & Mobile SW Check RX IQ Redownload SW or Do calibration again - 46 - - LG B2050 | Service Manual - Page 48
(1) Checking Regulator Circuit TEST POINT 4 . TROUBLE SHOOTING CIRCUIT CLKON Figure 4-2 VBAT C533 10u RF2V85 U702 MIC5255-85BM5 1 IN 2 OUT 5 3 GNO EN BYP 4 C734 0.01u C534 10u (1608) Checking Flow Voltage at - LG B2050 | Service Manual - Page 49
4 . TROUBLE SHOOTING (2) Checking VCTCXO Circuit TEST POINT Checking Flow Check Pin 3. 13 MHz O.K? Refer to Graph 4-1 (b) No Check Pin 4. 2.7V OK? Refer to Graph 4-1 (a) No Yes VCTCXO Circuit is OK See next Page to check ANT SW & Mobile SW Yes Changing X500 Check U101, PMIC CIRCUIT - LG B2050 | Service Manual - Page 50
(3) Checking FEM & Mobile SW TEST POINT 4 . TROUBLE SHOOTING CIRCUIT TP502 TP501 TP500 C500 NA C502 NA C503 NA Figure 4-5 C512 2.2p Waveform KMS-507 R512 0 R515 0 R517 0 ANT_SW3 GPO_10 ANT_SW2 GPO_11 ANT_SW1 GPO_9 FEM Control GSM & DCS Graph 4-3(a) - 49 - FEM Control PCS Graph 4-3(b) - LG B2050 | Service Manual - Page 51
with No RF Cable Connected Yes Check R512, R515, R517 Check whether FEM Set as RX mode Refer toTable 4-2 VC1 :Low or HIGH No VC2 :Low VC3 :Low Yes Check RF Level of FL500.1 (for GSM) & FL500.3 (for DCS) & FL500.5 (for PCS) Pin1 : ~ -62dBm No n 3,5 : ~ -63dB Yes FEM & Mobile SW is OK - LG B2050 | Service Manual - Page 52
(4) Checking RX IQ 4 . TROUBLE SHOOTING TEST POINT Waveform DIAG2 CIRCUIT RF2V85 C518 C519 0.022u 22p VDD2 32 30 31 29 27 28 GND4 Che ck C514, C516. Check if there is Any Major Difference Refer to Graph 4-4 Similar? Yes No Replace U500 Redownload software and calibration againg - 51 - - LG B2050 | Service Manual - Page 53
4 . TROUBLE SHOOTING 4.2 TX Trouble TEST POINT 13Mhz OSCILLATOR Mobile SW FEM TRANCEIVER LDO PAM - 52 - - LG B2050 | Service Manual - Page 54
START HP8960 : Test mode 62 CH, 7 level setting (TCH) 62CH, -60dBm setting (BCCH) Spectrum analyzer setting Oscilloscope setting Check regulator circuit Check VCTCXO Check FEM & Mobile SW Check PAM contral signal Check TX IQ Redownload SW or Do calibration again 4 . TROUBLE SHOOTING - 53 - - LG B2050 | Service Manual - Page 55
4 . TROUBLE SHOOTING (1) Checking Regulator Circuit TEST POINT CIRCUIT CLKON VBAT C533 10u U702 MIC5255-85BM5 1 IN 2 3 GNO EN 5 OUT BYP 4 C734 0.01u RF2V85 C534 10u (1608) - LG B2050 | Service Manual - Page 56
VCTCXO Circuit 4 . TROUBLE SHOOTING TEST POINT CIRCUIT Waveform 100 R514 Checking Flow Check Pin 3. 13 MHz O.K? Yes Refer to Graph 4-1 (b) No Yes Check Pin 4. 2.7V OK? Refer to Graph 4-1 (a) No Check U101, PMIC VCTCXO Circuit is OK See next Page to check ANT SW & Mobile SW Changing - LG B2050 | Service Manual - Page 57
4 . TROUBLE SHOOTING (3) Checking Ant SW & Mobile SW - 56 - - LG B2050 | Service Manual - Page 58
Checking Flow 4 . TROUBLE SHOOTING For the test, TX Stand alone Mode is needed. Refer to Pin 17 (for GSM) & Pin 15 (for DCS) Check SW500.ANT, RF with RF Cable connected. Check SW500.ANT, RF with RF Cable disconnected Pin17 : ~29.5dBm Pin15 : ~26.5dBm No Go to 4.3.5 Checking PAM control singnal - LG B2050 | Service Manual - Page 59
4 . TROUBLE SHOOTING (4) Checking PAM Control Signal TEST POINT Waveform 12 11 100 RF2V85 C518 C519 0.022u 22p TX_RAMP PA_BAND PA_EN TX_RAMP PAM_EN Band Select (R501) GSM TX_Low DCS/PCS TX_High Checking Flow Graph 4-7 Check TX_RAMP and PA_EN Check if there is Any Major Difference or not - LG B2050 | Service Manual - Page 60
(6) Checking TX IQt TEST POINT 4 . TROUBLE SHOOTING Waveform CIRCUIT DIAG2 RF2V85 C518 C519 0.022u 22p 31 32 30 28 29 27 VDD2 GND3 GND4 GND2 XOUT Flow Check if there is Any Major Difference Refer to Graph 4-8 Similar? Yes No Replace U500 Redownload the Software And calibrate - 59 - - LG B2050 | Service Manual - Page 61
SHOOTING 4.3 Power On Trouble TEST POINT 1V8_VCORE 2V8_VMEM 1V8_VRTC 2V85_VSIM 2V75_VABB 2V5_VMIC 2V75_VVCXO 2V8_VEXT BAT100 CIRCUIT VCORE1 VCORE2 VMEM1 VMEM2 VRTC VSIM VABB VMIC VVCXO NC_E15 VEXT1 VEXT2 VBAT_NET - LG B2050 | Service Manual - Page 62
VSIM=2.5V (when sim card is inserted) VMIC=2.5V NO Logic level at KEYON of U101 = HIGH YES NO Does it work properly? Re-download software Does it work properly? Check Battery Voltage > 3.35V ? NO YES THE PHONE WILL POWER ON. Replace the main board - 61 - - LG B2050 | Service Manual - Page 63
4 . TROUBLE SHOOTING 4.4 Charging Trouble TEST POINT CIRCUIT NC_T15 T15 R1 NC_R1 VMEMSEL R3 T5 GND_NET1 NC_G16 G16 B7 NC_B7 NC_B5 B5 B8 VBATSENSE VCHG A5 ISENSE A7 A6 GATEDRIVE - LG B2050 | Service Manual - Page 64
Checking Flow 4 . TROUBLE SHOOTING START I/O Connector (CN300) is well-solderd? YES Voltage at anode of D100 = D100 YES NO 0.7 < voltage(R109) < 1.3V? Replace the Q100 YES Battery is charged? NO The battery may have problems. Change the battery. YES Charging is properly operating - 63 - - LG B2050 | Service Manual - Page 65
4 . TROUBLE SHOOTING 4.5 Vibrator Trouble TEST POINT CIRCUIT VBAT MIDI_VIBRATOR C300 4.7u R315 1.5K U401 MIC5255-2.85BM5 1 IN OUT 5 2 GND 3 EN BYP 4 C302 0.01u C303 1u CN301 1 2 C301 1u R399 51K D300 1SS352 C304 27p - 64 - - LG B2050 | Service Manual - Page 66
4 . TROUBLE SHOOTING Checking Flow SETTING : Enter the engineering mode, and set vibrator on at vibration of BB test menu START NO Is the voltage at pin 3 - LG B2050 | Service Manual - Page 67
4 . TROUBLE SHOOTING 4.6 LCD Trouble TEST POINT - 66 - - LG B2050 | Service Manual - Page 68
Checking Flow 4 . TROUBLE SHOOTING START Check the soldering of CN400 ? YES Is the connection of FPCB with connector on PCB(CN400) ok ? YES Check the soldering of EMI - LG B2050 | Service Manual - Page 69
the earphone? Level 1,2,8,9 pin Of U700 is OK? YES NO Level YES 2,8,1,9 pin of U701 is OK? NO NO GO to 4.10 Earphone Trouble Check YES Soldering Component Around U701 OK? NO Check Soldering Component Around U700 OK? YES Resolder the component Change U700 NO Resolder the component - LG B2050 | Service Manual - Page 70
4.7 Speaker Trouble TEST POINT 4 . TROUBLE SHOOTING - 69 - - LG B2050 | Service Manual - Page 71
VCC 2 1 IN 3 GND 4 . TROUBLE SHOOTING CIRCUIT DIAGRAM 2V8_VEXT 2V8_VEXT C221 1u DATA15 DATA14 DATA13 DATA12 DATA11 B1 B2 DGND P0_PWMA E1 C6 P5_VIB AOUT B3 C224 E3 F3 ILE E2 CS RD F4 D1 WR RESET MIXIN A3 B4 MIXOUT VREF A1 C228 1u SPOUT+ A6 C222 1u 0.022u R224 20K R229 39K C226 - LG B2050 | Service Manual - Page 72
Checking Flow START 4 . TROUBLE SHOOTING Check the state of contact of dual mode speaker YES Check U202 works properly YES Check U206 works properly YES Check Voltage level of 4,5 - LG B2050 | Service Manual - Page 73
SHOOTING 4.8 SIM Card Interface Trouble TEST POINT CIRCUIT DIAGRAM SIM CONNECTOR 2V85_VSIM 2V85_VSIM A310 SIM_DATA VLC14S02050 R336 20K R337 0 J300 4 GND1 VCC 1 5 6 VPP RST 2 3 10 IO CLK GND5 GND2 7 9 GND4 - LG B2050 | Service Manual - Page 74
Checking Flow 4 . TROUBLE SHOOTING START Does the SIM cards supports 3V? NO Change the SIM Card. Our Phone supports only 3V SIM card YES NO Voltage at pin1 of J300 is 3V? YES Voltage at VSIM of U101 Is 3V? NO YES Replace J300 - LG B2050 | Service Manual - Page 75
SHOOTING 4.9 Earphone Trouble TEST POINT J200 U205 U200 U201 CIRCUIT DIAGRAM RADIO_SPK_R RADIO_SEL HEADSET_SPK_P 2V8_VEXT C227 10u R232 NA U205 NLAS4684MR2 1 V+ 10 NO2 2 NO1 9 COM2 3 COM1 8 IN2 4 IN1 7 - LG B2050 | Service Manual - Page 76
Checking Flow START Resolder J200 4 . TROUBLE SHOOTING Does the audio profile of the phone change to the earphone mode? NO Level at JACK_DETECT signal is low NO Resolder R123, R216 or Replace J200 YES YES Set the audio part - LG B2050 | Service Manual - Page 77
4 . TROUBLE SHOOTING 4.10 KEY backlight Trouble TEST POINT - 76 - - LG B2050 | Service Manual - Page 78
4 . TROUBLE SHOOTING CIRCUIT DIAGRAM KEY BACKLIGHT VBAT C318 1u C319 1u C320 S14H LEBB-S14H MIDI_KEY_BL1 MIDI_KEY_BL2 Checking Flow START NO Is the voltage level VBAT 3.6~4.2V? YES Charge battery Are all LEDs Working? NO Check the soldering each R and LED YES Backlight will work properly - LG B2050 | Service Manual - Page 79
SHOOTING 4.11 Receiver Trouble TEST POINT CIRCUIT DIAGRAM AGND2 AGND1 SGND1 SGND2 DGND LGND AOUT1P J15 K15 AOUT1N AOUT2P1 AOUT2P2 AOUT2N1 R11 T11 T9 R9 AOUT2N2 AOUT3P J16 AOUT3N K16 C2 GPI C143 C144 39p 39p R111 4.7 R114 4.7 C139 39p HEADSET_SPK_P HEADSET_SPK_N RINGTONE C140 C141 39p - LG B2050 | Service Manual - Page 80
Checking Flow 4 . TROUBLE SHOOTING SETTING : After initialize Agilent 8960, Test EGSM, DCS mode Set the property of audio as PRBS or continuous wave. Set the receiving volume of mobile as Max. START Check the state of NO contact of dual mode speaker (receiver) YES Reassemble receiver U202 - LG B2050 | Service Manual - Page 81
SHOOTING 4.12 Microphone Trouble TEST POINT CIRCUIT DIAGRAM 2V5_VMIC R200 1K MIC_P MIC_N C210 39p R207 100 R210 100 R203 2.2K R208 0 C211 0.1u C201 39p C202 10u C209 39p R214 2.2K C213 39p C214 39p CLOSE TO MIC MIC200 1 2 OB4-15L42-C33L VA201 VA200 AVL5M02-200 AVL5M02-200 - 80 - LG B2050 | Service Manual - Page 82
4 . TROUBLE SHOOTING Checking Flow SETTING : After intialize Agilent 8960, Test EGSM, DCS mode START NO NO Voltage across R200 Voltage VMIC of U101 Replace U101 = DC 2. - LG B2050 | Service Manual - Page 83
SHOOTING 4.13 RTC Trouble TEST POINT CIRCUIT DIAGRAM R110 10M BAT100 X100 MC-146_12.5pF 3 4 2 1 32.768KHz C129 1000p CLKON TP122 C130 NA PWRON _RESET RADIO_STO RADIO_DETECT SPK_RADIO_SEL N10 - LG B2050 | Service Manual - Page 84
Checking Flow START 4 . TROUBLE SHOOTING Is the voltage level of BAT100 > 1.2V? YES Check Soldering of R104, C112, C149 YES Check the voltage at 1,4 of X100 YES Change main board NO Charge or change BAT100 NO Resolder R104. C112, C149 NO Resolder R110, C130 or Replace X100 - 83 - - LG B2050 | Service Manual - Page 85
4 . TROUBLE SHOOTING 4.14 Indication LED Troublet TEST POINT Q301 Q401 CIRCUIT DIAGRAM VCHARGE VBAT C325 0.1u PRECHARGE R355 1.5K R357 10K 3 2 1 IMX9T110 Q301 4 5 6 R353 1K 2012,1% R352 15 R356 47K VBAT C324 0.1u LD306 R350 750 3 2 Q401 2SC5585 1 R358 10K R359 20 - 84 - - LG B2050 | Service Manual - Page 86
Checking Flow 4 . TROUBLE SHOOTING Indication LED only operates in trickle charging mode. START Voltage level at 3pin of Q401 Is about 40mV YES Check soldering of R350 YES Replace LD306 NO Voltage level at 2pin of - LG B2050 | Service Manual - Page 87
5. DOWNLOAD AND CALIBRATION 5. DOWNLOAD AND CALIBRATION 5.1 Download A. Download Setup Figure 5-1 describes Download setup UART Figure 5-1 DOWNLOAD SETUP - 86 - - LG B2050 | Service Manual - Page 88
5. DOWNLOAD AND CALIBRATION B. Download Procedure 1. Access Flash loader program in PC and select Erase(Don't check OWCD). 1. Select Port 2. Select Rate 3. Select Hermes 4. Select Erase 5. Insert FDI region 6. Donʼt Check OWUD 2. Pre2s. sPSretsasrtSatanrdt aWnaditWuanittiluEntrial - LG B2050 | Service Manual - Page 89
5. DOWNLOAD AND CALIBRATION 3. Press Write to start Download and press key to choose software (AlchemyDate.mot) 1. Select Port 2. Check 3. Check - 88 - - LG B2050 | Service Manual - Page 90
4. C4h. Coohsoeosseofstowftawreare 5. DOWNLOAD AND CALIBRATION 1. Select File 2. Press Open 5. W5.aWit auitnutinl tcilocvoevretirntigngfrofrmomMMOOTTtotoBBIFIFisisccoommppleted (Doonn'ʼttcchheecckkOOWWUUDD) ) 3. Wait until completion 1. Donʼt Check OWUD - 89 - - LG B2050 | Service Manual - Page 91
5. DOWNLOAD AND CALIBRATION 6. Press Start and Pover on the phone using JIG remote Power on (Switch 1) - 90 - - LG B2050 | Service Manual - Page 92
5.2 Calibration 5. DOWNLOAD AND CALIBRATION - 91 - - LG B2050 | Service Manual - Page 93
5. DOWNLOAD AND CALIBRATION - 92 - - LG B2050 | Service Manual - Page 94
3rd, 4thof DIP SW ON state always 4. Press the Phone power key, if the Remote ON is used, 1stON state D. Procedure 1. Connect as Fig 6-2(RS232 serial cable is connected between COM port of PC and MON port of TEST JIG, in general) 2. Power ON PC then enter into Windows 98(Remark : Windows 2000 system - LG B2050 | Service Manual - Page 95
(128X128) MCP (128X32) CS/WR/RD/DIMM C O ADD0 N N DATA(0:15) ADDR(0:23) ROM_CS,RAM_CS RD/WD/RST/... DATA ( ADDRESS ( A VIBR ATOR TR D 6 0 .. 5 KEY KEYROW D 2V5_VMIC 6 POWERKEY 5 GATE 3 DRIVE 7 LIGHT LIGHT B KEYPAD LED VOUTNOR AOTU1 13 S G FET D VBAT AINI VINNOR AIN2 - LG B2050 | Service Manual - Page 96
6. BLOCK DIAGRAM BEE Project RF Block Diagram - 95 - 6. BLOCK DIAGRAM - RF VBAT ANT S/W DCS,PCS_OUT GSM_OUT GSM_IN DCS_IN PCS_IN TX_RAMP PA_EN PA_BAND PAM (RF3166) FEM (Murata) 2V75_VTCXO 13MHz DCS,PCS_IN GSM_IN B RXI RXO A TXI TXQ S Tranceiver E (SI4205) RF_PD S_EN S_CLK B - LG B2050 | Service Manual - Page 97
- LG B2050 | Service Manual - Page 98
RINGTONE USB BOOT INT CLOCK KEY_COL2 H H USB QP QN AFCDAC PA RESET KEYOUT KEYON DBBON VCXOEN CHGOSC NC 0.01uF 10 GUIDE HOLE OJ1 OJ2 OJ3 REC_P REC_N HEADSET_SPK_P HEADSET_SPK_N RINGTONE C140 C141 39p H.J. LEE S.Y. KIM B.Y. DRAWING NAME B2050 Sheet/Sheets 1/5 Hermes 6527 ,Typhoon 6537B - LG B2050 | Service Manual - Page 99
BB CLOSE TO MIC Q200 IMX9T110 MIDI_KEY_BL1 D1 1 10 2V8_VEXT _MIDI_RESET RESET A6 V+ NO2 SPOUT+ VBAT RADIO/SPEAKER PHONE SEL RADIO_SEL B2050 Sheet/Sheets 2/5 E Checked Approved 2004. 12.08 2004. 12.08 LEE S.Y. KIM B.Y. DRAWING NAME AUDIO/MIDI Iss. Notice No. Date Name LG - LG B2050 | Service Manual - Page 100
USC5 USC6 DAI CLOCK RX TX - RESET UART RXD TXD RTS/CTS(PC) CTS/RTS(PC) - R329 47 R334 1K R333 NA E4 _WP _ROM_CS2 _F_WP Designer 2004. 12.08 KIM H.J. MODEL B2050 3/5 C4 E5 VSS2 _ADV _ADV L1 F5 E C327 1u C329 Name LG Electronics Inc. DRAWING NO. Ver.1.0 1 2 3 4 5 LGIC(42)-A-5505- - LG B2050 | Service Manual - Page 101
D 2SC5585 R488 51K R406 220K Name Section Designer Checked Approved Date 2004. 12.08 2004. 12.08 2004. 12.08 Sign & Name KIM H.J. LEE S.Y. KIM B.Y. LG Electronics Inc. MODEL DRAWING NAME DRAWING NO. B2050 Sheet/ Sheets 4/5 LCD CONN,RADIO Ver - LG B2050 | Service Manual - Page 102
GPO_19 GPO_20 A B C AFC D Section Designer Checked Approved Date 2004. 12.08 2004. 12.08 2004. 12.08 Sign & Name KIM Y.G. MODEL LEE S.Y. KIM B.Y. DRAWING NAME B2050 Sheet/Sheets 5/5 RF Iss. Notice No. Date Name LG Electronics Inc. DRAWING NO. Ver - LG B2050 | Service Manual - Page 103
8. PCB LAYOUT - 102 - Figure 8-1 B2050 BOTTOM SIDE PCB LAYOUT - LG B2050 | Service Manual - Page 104
8. PCB LAYOUT - 103 - Figure 8-1 B2050 TOP SIDE PCB LAYOUT - LG B2050 | Service Manual - Page 105
- LG B2050 | Service Manual - Page 106
Mode Engineering mode is designed to allow a service man/engineer to view and test the basic functions provided by a handset. B. Access Codes The key sequence for switching the engineering mode on Test RF Test MF Mode Trace option Call Timer Fact. Reset S/W Version FM Radio ⑨ - 105 - - LG B2050 | Service Manual - Page 107
on at the same time. 2) Backlight off : LCD Backlight and Keypad Backlight light off at the same time. 3) Backlight value : This controls brightness of Backlight. When entering into the menu,the present backlight-value in the phone is displayed. Use Left/Right key toadjust the level of brightness - LG B2050 | Service Manual - Page 108
Battery ADC 2) AUX ADC : Auxiliary ADC 3) TEMPER ADC : Temperature ADC 9.1.7 BATTERY 1) Bat Cal : This displays the value of Battery default value after switching off and on the phone test This menu is to test the Specific Absorption Rate. 1) SAR test on: Phone continuously process TX only. Call-setup - LG B2050 | Service Manual - Page 109
the baseband test automatically. Selecting this menu will process the test automatically, and phone displays the previous menu after completing the test. 9.3.1 All auto test LCD, Backlight, Vibrator, Buzzer, Key Pad, Mic&Speaker, 9.3.2 Backlight LCD Backlight is on for about 1.5 seconds at the same - LG B2050 | Service Manual - Page 110
Factory Reset) should be only used during the Manufacturing process. 2) Servicemen should NOT progress this menu, otherwise some of valuable data such as Setting value, RF Calibration data, etc. cannot be restored again. 9.7 S/W version [MENU 7] This displays software version stored in the phone - LG B2050 | Service Manual - Page 111
This manual explains how to examine the status of RX and TX of the model. A. Tx TestTX test -this is to see if the transmitter of the phones is : select a correct COM port -Baud rate : 38400 -Leave the rest as default values B. Tx 1. Selecting Channel -Select one of GSM or DCS Band and input - LG B2050 | Service Manual - Page 112
10.3 Means of Test a. Select a COM port b. Set the values in Tx or Rx c. Select band and channel d. After setting them all above, press connect button. e. Press the start button 10. STAND ALONE TEST - 111 - - LG B2050 | Service Manual - Page 113
10. STAND ALONE TEST - 112 - - LG B2050 | Service Manual - Page 114
data block of flash memory in GSM phone. 11.2 Requirements -PC or Notebook installed with Microsoft Windows 98/ME/2000/XP -Auto Calibration program(Autocal.exe) -GSM Phone -LGE PIF JIG, Serial Cable, Data Cable only : Make binary file of battery cal data only after calibration finished -File(F) Make - LG B2050 | Service Manual - Page 115
Calibration Program Screen Screen Screen Screen Cable loss : Enter the RF cable loss GSM and DCS GPIB(Primary address) : Enter the SS(Ag8960) and PS(Tektronix PS2521G) GPIB address ADC Channel : Default ADC Calibration Channel Auto Calibration Item : Default Calibration Settings about Tx, Rx, ADC - LG B2050 | Service Manual - Page 116
and gain code and battery calibration.You can get main Battery Config Table and temperature ConfigTable 11.7 Setting check com port and cable cable between phone and serial port of PC. B. Connect Ag8960 equipment and Power Supply and phone data will be written into phone and thenwill be reset. - 115 - - LG B2050 | Service Manual - Page 117
- LG B2050 | Service Manual - Page 118
12. EXPLODED VIEW && REPLACEMENT PART LIST 12.1 Exploded View 9 4 3 2 1 5 6 26 25 12 11 10 8 22 23 29 7 28 13 24 14 17 15 16 21 27 20 19 18 - 117 - - LG B2050 | Service Manual - Page 119
- LG B2050 | Service Manual - Page 120
Description GSM,BAR/FILP 2 AAAY ADDITION 3 MCJA COVER,BATTERY 2 APEY PHONE 3 ACGK COVER ASSY,FRONT 4 AWAB00 WINDOW ASSY,LCD MTAZ00 TAPE 3 AKAZ KEYPAD ASSY 3 GMEY00 SCREW MACHINE,BIND 3 GMZZ00 SCREW MACHINE 3 MCCF00 CAP,MOBILE SWITCH 3 MCCH00 CAP Specification Color - LG B2050 | Service Manual - Page 121
,MAIN,INSERT 5 SBCL00 BATTERY,CELL,LITHIUM 5 SUMY00 MICROPHONE Specification SUSY0014801 PIN ,8 ohm,88 dB,20 mm,*14mm SJMY0007001 3 V,0.085 A,4*12.5 ,6.6T,L3100,SILINDER SAFY0125201 B2050 PCB ASSY MAIN SAFB0040301 B2000/B2050 MAIN INSERT SBCL0001303 2 V,1 mAh,COIN ,SOLDER TYPE BACKUP BATTERY - LG B2050 | Service Manual - Page 122
CAP,TANTAL,CHIP,MAKER 6 C228 CAP,CERAMIC,CHIP 6 C229 CAP,CERAMIC,CHIP 6 C231 CAP,CERAMIC,CHIP 6 C232 CAP,TANTAL,CHIP,MAKER Part Number Specification ECCH0000143 1 nF,50V,K,X7R,HD,1005,R/TP ECCH0000143 1 nF,50V,K,X7R,HD,1005,R/TP ECTH0001701 10 uF,6.3V ,M ,L_ESR ,2012 ,R/TP ECCH0000143 - LG B2050 | Service Manual - Page 123
RES,CHIP 6 C503 CAP,CERAMIC,CHIP 6 C504 CAP,CERAMIC,CHIP 6 C505 CAP,CERAMIC,CHIP 6 C507 CAP,CERAMIC,CHIP 6 C508 CAP,CERAMIC,CHIP Part Number Specification ECCH0000122 47 pF,50V,J,NP0,TC,1005,R/TP ECCH0000122 47 pF,50V,J,NP0,TC,1005,R/TP ECTZ0005201 10 uF,6.3V ,M ,L_ESR ,1608 ,R/TP - LG B2050 | Service Manual - Page 124
C733 CAP,CERAMIC,CHIP 6 C734 CAP,CERAMIC,CHIP 6 CN300 CONNECTOR,I/O 6 D100 DIODE,SWITCHING 6 D101 DIODE,SWITCHING 6 D300 DIODE,SWITCHING Part Number Specification ECCH0000110 10 pF,50V,D,NP0,TC,1005,R/TP ECTZ0003101 33 uF,10V ,M ,STD ,ETC ,R/TP ECCH0000117 27 pF,50V,J,NP0,TC,1005,R/TP - LG B2050 | Service Manual - Page 125
RES,CHIP 6 R118 RES,CHIP 6 R130 RES,CHIP 6 R131 RES,CHIP 6 R201 RES,CHIP 6 R202 RES,CHIP 6 R204 RES,CHIP Part Number Specification SFEY0006401 SMD ,6 Channel, EMI+ESD, CSP SFEY0006401 SMD ,6 Channel, EMI+ESD, CSP SFEY0006401 SMD ,6 Channel, EMI+ESD, CSP SFEY0006401 SMD ,6 Channel - LG B2050 | Service Manual - Page 126
RES,CHIP 6 R316 RES,CHIP 6 R317 RES,CHIP 6 R319 RES,CHIP 6 R320 RES,CHIP 6 R321 RES,CHIP 6 R323 RES,CHIP Part Number Specification ERHY0000265 20K ohm,1/16W,J,1005,R/TP ERHY0000265 20K ohm,1/16W,J,1005,R/TP ERHY0000287 220K ohm,1/16W,J,1005,R/TP ERHY0000202 4.7 ohm,1/16W,J,1005 - LG B2050 | Service Manual - Page 127
6 R501 RES,CHIP 6 R502 RES,CHIP 6 R503 RES,CHIP 6 R504 RES,CHIP 6 R505 RES,CHIP 6 R506 RES,CHIP 6 R507 RES,CHIP Part Number Specification ERHY0000237 680 ohm,1/16W,J,1005,R/TP ERHY0000213 47 ohm,1/16W,J,1005,R/TP ERHY0000213 47 ohm,1/16W,J,1005,R/TP ERHY0000213 47 ohm,1/16W,J,1005 - LG B2050 | Service Manual - Page 128
VARISTOR 6 VA310 VARISTOR 6 VA311 VARISTOR Part Number Specification Color ERHY0000224 180 ohm,1/16W,J,1005,R/TP ERHY0000201 0 128T+32ps(MLC) 8X10 EUSY0238201 QFN ,16 PIN,R/TP ,3 LEDs, WHITE LED CHARGE PUMP EUSY0118602 SOT23 ,5 PIN,R/TP ,2.85V/150mA Low Noise uCap LDO Regulator - LG B2050 | Service Manual - Page 129
6 VA331 VARISTOR 6 VA332 VARISTOR 6 VA333 VARISTOR Part Number Specification SEVY0001001 14 V, ,SMD ,50pF, 1005 SEVY0001001 14 V, ,SMD ,SV 2.85V, AFC 0.8V 5 SAFD00 PCB ASSY,MAIN,SMT TOP SAFD0047001 B2050 PCB ASSY,MAIN,SMT TOP 6 C201 CAP,CERAMIC,CHIP ECCH0000120 39 pF,50V,J,NP0 - LG B2050 | Service Manual - Page 130
RES,VARIABLE,ETC 5 SPFY PCB,MAIN 3 SNGF00 ANTENNA,GSM,FIXED Part Number Specification ERHY0000213 47 ohm,1/16W,J,1005,R/TP ERHY0000213 47 ohm,1/16W,J,1005,R/TP ERHY0000213 47 FR-4 ,1.0 mm,BUILD-UP 8 , SNGF0006401 3.0 ,-2 dBd, ,EGSM+DCS+PCS, Radio Intenna Color Remark 10 - 129 - - LG B2050 | Service Manual - Page 131
3 SBPL00 BATTERY PACK,LI-ION 3 SSAD00 ADAPTOR,AC-DC 3 WSAY00 SOFTWARE,APPLICATION 3 WSYY00 SOFTWARE Part Number Specification SBPL0077901 3.7 V,830 mAh,1 CELL,PRISMATIC ,FG101 RUSSV423450, Innerpack SSAD0007835 FREE ,50 Hz,5.2 V,800 mA,CE,CB ,UK(IO.24P) WSAY0014101 B2050 TMU PC-Sync - LG B2050 | Service Manual - Page 132
- 131 - - LG B2050 | Service Manual - Page 133
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B2050
Service Manual
B2050
P/N : MMBD0049101
Date : April 2005
/ Issue 1.0
B2050Cover_3.3-0419
2005.4.20 1:7 PM
Page 2